Manufacture of hydraulic cement and apparatus therefor.



PATBNTBD. MAR. 13, 1906.

' B. BNRIGHT. MANUPAGTURE 0F HYDRAULIC CEMENT AND APPARATUS THBRBPOR.

APPLICATION FILED OCT. 2, 1905..

his

.n rv u INVENTOR 50:52am? mlp.

BY HIS NTToRNEVs v1\'r0.'815,080. PATBNTED MAR. 1s, 1000. n B. ENR-10m. MANUPACTURE 0F HYDRAULIC CEMENT AND APPARATUS THBR-EFOR.

I APPLICATION FILED OCT. Z, 1905.

2 SHEETS-SHEET 2.

BY' H |S TTORNEYS 4o from the charge in the vertical kiln.

5o dioxid present.

UNTTED sTATEs PATENT OFFICE.

BERNARD ENRIGHT, OF FORDVVICK, VIRGINIA.

MANUFACTURE OF HYDRAULIC CEMENT AND APPARATUS THEREFOR.

Specification of Letters Patent.

` Application filed October 2, 1905. Serial No. 281,005.

" all whom, it may concern:

Be it known that I, BERNARD ENIGHT, analytical chemist, a citizen of the United States, residing at Fordwick, in the county of `iAugusta and State of Virginia, have invented certain new and useful Improvementsin the Manufacture of Hydraulic Cement and Apparatus Therefor, of which the following is a specification.

In the manufacture -of Portland cement by the rotary-kiln process there has heretefere been great waste of fuel and heat, owing prinf cipally to\ the fact that the rapid and intense i combustion required for properly clinkermg i5 the cement material results in a large volume of heated gases passing through the stack of the furnace. The cement-rock or carbonate of lime burned in the rotary'kiln gives off a large volume of carbon dioxid, which is an 2o incombustible gas and which generally goes to waste, although it has been proposed to convert this gas .into carbon monoxid, which' is a combustible gas, and to use such gas for various purposes, elther'by returning it to the kiln, storing it in gasometers, or enriching it for illuminating purposes. I have found that great yeconomyjin the manufacture of Por andand other cements results from causing the gases from a'rotary kiln to 3o pass through a vertical kiln charged with alternate layers of cement-rock, limestone, and

the like and a fuel, such as coal or coke.

By properly regulating the temperaturev in the vertical kiln and by. properly controlling the chemical combinations therein the carbon dioxid passing from the rotary kiln and` through the vertical kiln may be converted into carbon monoxid and commingled or combined with the carbon-monoxid produced I have also found'that the charge of cement rock or limestone thus treated in the vertical kiln is rendered friable or suitable for grinding and is in better condition for treatment in the rotalrvy' kiln, Where the clinkering is performed.

he gases issuing from the vertical lkiln are largely composed of carbon monoxid; 1 The nitrogen and other such gases neednot be considered; but there is also some carbon This can be convertedinto carbon-monoxid by being passed through'incandescent fuel, as in a gas-producer. -Such gases issuing 'from the Vertical kiln, eitherv with or without being assed through a gasproducer, may be emp oyed to operate as-` engines, may be stored 'for use as nee ed,

` vdisfchargin may be employed to heat steam-boilers, may be returnedto the rotary kiln,y or may be en= riched for illuminating purposes.

In case the temperature of the gas issuing from the vertical kiln is too great it can be drawn through absorbers, where thetemperature of the gas will be reduced, and these absorbers may be employed to raise the heat of the air admitted to the vcrtiealkiln to promote combustion therein.

The temperature in the vertical ykiln maybe regulated and some hydrogen may be supplied, if needed, by the introduction of steam in said kiln, and the gases issuing from the kiln may be purified, if necessarv, by being passed through a scrubber.

rotary kiln may be employed to assist in "roducing slag for slag cement in a suita lyformed kiln or furnace, and, indeed, these gases. may beemployed, in furnaces having ordinary blast-furnace charges.

In the accompanying drawings, Figure l shows diagrammatically an apparatus em` Patented March 13, 1906.

I have found also that kthe products of combustion issuing from a The rotary kiln A may be of any approved y type. `Fuel in the form of was, dered.' coal may be supplied may be admitted at a2,

oil, or powat a', and air The upper or gasend of the kiln extends into a casing or lower art of thev vertical kiln E.

l,mentorming. material may be supplied to the kiln through a conveyer-AC Y -It is im ortant that no air shall enter at the joint o the kiln A and housin B, because if the draft 'throu' h'thevertica kiln is too Vfree an undesirabe amount of air will be drawn into the apparatus, and, on the other hand, if the draft through the vertical kiln is choked or is impeded a back pressure might result which would force the products of combustion around the outside of the rotary kiln. I therefore provide an air-tighty conousing B, which communicates, through a flue C, with a rshaft D, forming the IOO.

nec-tion which preferably, as shown in Fig. 3, consists of a ring a, secured to the kiln A, and a ring Z), secured to the housin B. It will be observed that the ring ais ine ined relatively to the adjacent wall of the housing and lits the kiln tightly. It has an inclined periphery which fits snugly the ring b. The contacting surfaces "are made smooth or are machined so as to run free without permitting the ingress or egress of lair or other gases. The

same result may be obtained by inclining the wall of the housing B, as indicated in Fig. 4, and arranging the rings in the manner shown.

Baffie-plates c c are employed to arrest the dust, or a large portion of it, entering the housing and to direct it into a trough B', from which it may be removed automatically or otherwise in any suitable way.

The housing or dust-chamber B is provided with a stack B2, having a valve b2. This stack, which I call the emergencystack, is only used when for any reason it is undesirable to pass the roducts of combustion into the vertical kiln or when it is desired to relieve the pressure in the chamber B. The vertical ki n" may be cut off-from Preferably the.

the housing' by a valve D. vertical kiln E is of the form shown, resembling in general outlines anold-fashion limekiln or a blast-furnace. It is provided with a grate G, on which the charge rests, and charging devices H, similar to those used in blast-furnaces, are preferably employed.

The charge in the vertical kiln preferably consists of alternate layers of coke, coal, or other like suitable fuel, and cementrock,uce1nentrock and limestone, or any other suitable mixture of like nature. The material is preferably charged in rather lar e lumps, so as to permit a suitable dra t.

Combustion may be started in thecharge by aid of theproducts of combustion from the rotary kiln, and `the products of combustion from -the vertical kiln pass out through the outlets E and At the lower portionof the shaft D, I arrange hinged doors J, below which is a compartment K. The `burned lime-rock or cement-rock is received on the doors J while the door K of the compartment K is closed. Then these doors J are lowered, emptying the charge of burned lime or cement rock into the compartment K, and then the Ydoors J are raised, affording an air-tight closure. The burned material may then be removed from the compartment K, ground in the usual way, and fed to the rotary kiln, where the clinkering is performed. I have found that the material burned or partially calcined in this way is not only more easily ground, but it is more readily converted into clinker in the rotary kiln and less fuel is rei quired therein. I

Air may be adnnttedto promote combustion through the twyers L L', and steam may be admitted at m in order to reduce, if necessary, the temperature in the vertical kiln and to supply hydro en, if needed. The twyers may e assisted y means of steam-jets supplied by the branch pipe M from the maln steam-pipe M.

If the heat of the gases issuing from the vertical kiln is too great, the temperature may be reduced bv passing them through absorbers N N, which are connected with the pipe or assage O in such manner that either one o them can be used to the exclusion of the other, and there are separate outlets, so that either one may be cut off from the pipe O, which conveys the gas froln the absorbers. Preferably the absorbers -consist, as indicated, of casings filled with firebrick, resembling ordinary regenerators. Each 'absorber is rovided with an air-inlet P. Assuming that t 1e absorber N is connected with the supply-pipe O, the hot gas may be made to pass through the absorber and out into the outlet-pipe O. The absorber N is at this time disconnected from the pipes O and 0'; but its air-inlet may at this time be open and air may enter theabsorber through the inlet P and pass to' the pipe Q, which feeds the twyers L L. In this way the heat of an absorber may be reduced, while at the same time the temperature of the air fed to the vertical kiln may be increased. After the temperature of the absorber N is reduced and the temperature of the absorber N has been too much increased the valves may be shifted and the absorber N used to reduce the temperature of the gases from the vertical kiln, whilevthe absorber N is empldyed to raise the tem erature of the air fed to the twyers L L. fter the tem erature of the gases has been thus reduced t ley may pass through the pipe and through a fan or blower O2 and either pass through the pi e o to a gasometer or other suitable place or use or through a branch pipe o to a gas-engine O3.

The natural draft of the vertical kiln may be sufiicient so that artificial means, such as a fan or blower, may be unnecessary.

While the gases issuing from the vertical kiln largely consist of carbon monoxid, any carbon dioxid which they contain may be converted into carbon monoxid by being passed through incandescent coke, coal, or charcoal. For this purpose I preferably employ two chambers R R', having air-inlets 1", and which are connected with the housing B by valved passages r R, and both of the chambers are connected by valved passages with an outlet-pipe S. The arrangement, as clearly indicated, is such that the products of combustion, or some of them, from the rotary kiln `may be passed through the chambers li R for the purpose of raising the fuel therein to incandescence when starting. The chambers may be used alternately. .For instance,

IOO

the chamber R may be connectedwith the chamber B and the fuel in the chamber R raised to incandescence while the chamber R is being used as a gas-producer in the mannerv Both the chambers R' presently explained. lt are connected with a pipe R2, which communicates wit-li a pipe E3, connected with the outlet-pipe E. The gas from the vertical kiln may be passed through a pipe E2 and be consumed or stored without further treatment, or the gases may be passed through the pipes E3 and R2 to the gas-producers R R', Where any carbon dioxid which they contain may be converted into carbon monoxid or producer-gas. Such gas is conveyed through a pipe T to a fan T5, which preferably. delivers to a gas-scrubber T', from which the gas may pass by means ofa pipe T2, and this may have a branch pipet, leading to a gas-engine T3, which may be employed to operate a tubemill T4 or any other machine or apparatus in the plant. If desired, the gas from the vertical kiln may be conveyed, as indicated, to the rotary kiln, a fan A2 being employed to assist its passage thereto.

The vertical kiln E may be operated at a comparatively low temperature-Ji. e., a temperature only high enough for the expulsion 'of Acarbon dioxid from limestone, cementroek, &c., and for the conversion of such carbon dioxid into carbon monoXid, as after carlbon dioxid is produced it will be largely if not wholly reduced to carbon nionoxid durin f its passage through the kiln. This verticall` kiln may be also operated at a somewhat vhighertemperature to promote the necessary `chemical reactions between lime, silica, and

alumina to produce` natural or Portland cement from cement-rock, cement-rock and limestone, vor other suitable material.

In oider to produce slag for slag cement or Passow cement, apparatus such as indicated in Fig'. 2 is prefera y employed. This ap aratus is similar in many respects to that efore described; -but the vertical kiln or furnace V is of the ordinary blast-furnace type. W indicates the twyers, and W the cinderlnotch. The products of Icombustion pass .from the chamberB through the conduit C to a bustle-pipe U, having branches U that deliver near the bottom of the boshes or at the upper ,part of the'hearth. In this instance a` much higher temperature should be maintained. The 'carbon dioxid from the-rotaryy 4kiln is converted into, carbon monoxid in its t-will be observed that the two kilns shownlin Fig. 1 operate under opposite conditions in some respects. ,Suflcieiitair is admitted to the rotary kiln to produce-an oxidizing atmosphere m which the carbon dioxid liberated fromv the charge is substantially unchanged and the fuel is converted Wholly or toa very large extent into carbon dioxid,

While in the vertical kiln a much smaller amount of air is admitted, producing a reducing-atmosphere in which the fuel burned and the carbon dioxid liberated from the charge, as well as the carbon dioxid from the rotar f kiln, are reduced largely if not wholly tocar- Abon monoxid during their passage through the kiln. This feature of my invention is 1in-- portant. Heat in the vertical kiln is preferablyconcentrated near the bottom thereof. Suilicient oxygen is supplied to produce carbon dioxid in the lower portion of the kiln, while care is taken that there shall be a deficiency of oxygen in the upper portion of the kiln in order 'that carbon monoXid may be formed.`

l claim as my invention- 1. The herein-described process which consists in causing the highly-heated gaseous products of combustion and decomposition from a rotary clinker-forming cement-kiln to pass through a CO2-producing charge containing carbon in a. kiln or furnace in which the temperature and conditions are such as to cause CO., to be liberated from the charge and the carbon dioxid issuing from the rotary kiln and the carbon` dioxid formed onset free in the Vertical kiln or furnace to be converted (or largely so) into carbon monoxid then collecting or utilizing the' carbon monoxid thus formed and collecting andusing the cementforniiiig material thus produced.

2. The hereiii-described process which consists in causing the highly-heated gaseous roducts of combustion and decomposition om a rotary cliiiker-forniing cement-kiln to rom a rotary clinker-forming kiln to pass through an incandescentcharge of fuel and icemeiit-producing material in a vertical kiln,

causing the cement-producing material to be partial y or completely ealcined andell'ecting a change lof the carbon dioxid issuineF from the rotary kiln and the carbn dioxid formed.

or set free at the lowerpart of the vertical kiln 1 nto carbon monoxid then collecting or utilizin the carbon -monoxid thus produced and colecting for use the cement-forming `material thus'produced. 4

4. Theherein-described process which com' sists in passing the highly-heated gaseous IOC IIO

iso

l products of combustion and decomposition from a clinker-forming rotary cement-kiln through a charge of incandecsent fuel and cement-forming material maintained at such temperature and under such conditions as to convert the carbon dioxid in said products of combustion and the carbon dioxid from the charge in the vertical kiln into carbon monoxid at the same time partially or completely calcining the cement-forming material and in collecting for use the calcined or partiallycalcined cement-forming material.

5. The herein-described process which consists in passing the highly-heated gaseous iirroducts .of combustion and decomposition om a clinker-forming rotary cement-kiln through a charge of incandescent fuel and cement-formin material in a vertical kiln producing a reucing-atmosphere in said vertical kiln to change the carbon dioxid received from the rotary kiln and the carbon dioxid formed or set free in the vertical kiln into carbon monoXid and at the same time artially or completely calcining the cementlbrmimT material then collecting or utilizing the carlbon monoxid thus produced and collecting for use the calcined cement-forming material.

6. The process herein described which consists in passing the highly-heated gaseous roducts of combustion and decomposition iE-)rom a clinker-forming rotary cement-kiln through a charge of cement-producing material and a relatively small proportion of incandescent fuel to largely convert the carbon dioxid in the products of combustion into carbon monoxid and then passing the resulting gases through incandescent fuel to reduce any carbon dioxid in said gases to carbon monoxid.

7. The combination of a rotary clinkerforming cement-kiln, a separating-chamber connected therewith, a vertical kiln connected with said separating-chamber, chambers containing coke or similar fuel also connected with the separatin -chamber and with the vertical kiln and evices for directing the roducts of combustion from the rotary kiln into either of said fuel-containing chambers and for directing gases issuin from the vertical kiln into e1t 1er of sald uel-contalnlng chambers.

8, The combination of a rotary clinkerforming cement-kiln, a separating-chamber connected therewith, a vertical kiln connected with said chamber and containing fuel and cement-producing material, an emergency-stack in the separating-chamber airlast and steam-supplying means at the lower portion of the vertical kiln and means for carr ing off the gases issuing from the vertical 'ln.

9. The combination of a rotary clinkerforming cement-kiln, a vertical kiln connected therewith, air-inlets in the vertical kiln, absorbers connected with the vertical kiln and also with the air-inlets, means for passing the gases issuing from the vertical kiln through the absorbers, devices for passing through the absorbers the air admitted to the vertical kiln, and means for supplyin tileam to the lower portion of the vertica 10. The combination of a rotary clinkerforming cement-kiln, a vertical kiln connected with the rotary kiln, a compartment below the vertical kiln for receiving burned rock, doors se arating this compartment from the vertical ki n, an emergency-stack connected with the rotary kiln and a damper interposed between the vertical kiln and the cement-kiln.

11. The combination of a rotary clinkerforming cement-kiln, a separating-chamber connected therewith, a vertical kiln connected with said separatin -chamber, means surrounding the rotary kn to exclude air from the separating-chamber, an emergency-stack in the separating-chamber, and means cutting ofi' the vertical kiin from the separatingchamber.

12. The combination of a rotary clinkerforming cement-kiln, a 4separating-chamber connected therewith, a vertical kiln connected with said se arating-chamber, a rin having an inclined) periphery secured to t e rotar kiln, and a rin having an inclined perip ery fitting the rst-mentioned ring and attached to the separatiu -chamber.

In testimony whereof I ave hereunto subscribed my name,

BERNARD ENRIGHT` Witnesses:

NEWTON C. WA'rrs, AUBREY BURNETT,

IDO 

